The present invention relates to a discrete-ratio gearbox for motor vehicle.
In conventional discrete-ratio gearboxes for motor vehicles, the shift travel limits of the various gear ratios are defined by the gear shift mechanisms themselves and therefore axial movements of the abutment surfaces defining the shift travel limits for the respective gear ratios, which are due to imperfect flatness and perpendicularity of the abutment surfaces and to the taking-up of axial play during the reversal of the axial thrust between drive and release because of the helical teeth of the gear wheels that define the gear trains associated with the various gear ratios, are transmitted to the respective sliding engagement sleeves, then to the respective shift forks and finally to the gear-change lever, thereby causing this latter to vibrate.